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Xiong S, Lin S, Hu Y, Xia W, Wang Q, Wang L, Cao T, Liao Y, Scholze A, Tepel M, Zhu Z, Liu D. Dietary Cinnamaldehyde Activation of TRPA1 Antagonizes High-Salt-Induced Hypertension Through Restoring Renal Tubular Mitochondrial Dysfunction. Am J Hypertens 2024; 37:708-716. [PMID: 38820173 DOI: 10.1093/ajh/hpae068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/25/2024] [Accepted: 05/13/2024] [Indexed: 06/02/2024] Open
Abstract
BACKGROUND The renal proximal tubule (RPT) plays a pivotal role in regulating sodium reabsorption and thus blood pressure (BP). Transient receptor potential ankyrin 1 (TRPA1) has been reported to protect against renal injury by modulating mitochondrial function. We hypothesize that the activation of TRPA1 by its agonist cinnamaldehyde may mitigate high-salt intake-induced hypertension by inhibiting urinary sodium reabsorption through restoration of renal tubular epithelial mitochondrial function. METHODS Trpa1-deficient (Trpa1-/-) mice and wild-type (WT) mice were fed standard laboratory chow [normal diet (ND) group, 0.4% salt], standard laboratory chow with 8% salt [high-salt diet (HS) group], or standard laboratory chow with 8% salt plus 0.015% cinnamaldehyde [high-salt plus cinnamaldehyde diet (HSC) group] for 6 months. Urinary sodium excretion, reactive oxygen species (ROS) production, mitochondrial function, and the expression of sodium hydrogen exchanger isoform 3 (NHE3) and Na+/K+-ATPase of RPTs were determined. RESULTS Chronic dietary cinnamaldehyde supplementation reduced tail systolic BP and 24-hour ambulatory arterial pressure in HS-fed WT mice. Compared with the mice fed HS, cinnamaldehyde supplementation significantly increased urinary sodium excretion, inhibited excess ROS production, and alleviated mitochondrial dysfunction of RPTs in WT mice. However, these effects of cinnamaldehyde were absent in Trpa1-/- mice. Furthermore, chronic dietary cinnamaldehyde supplementation blunted HS-induced upregulation of NHE3 and Na+/K+-ATPase in WT mice but not Trpa1-/- mice. CONCLUSIONS The present study demonstrated that chronic activation of Trpa1 attenuates HS-induced hypertension by inhibiting urinary sodium reabsorption through restoring renal tubular epithelial mitochondrial function. Renal TRPA1 may be a potential target for the management of excessive dietary salt intake-associated hypertension.
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Affiliation(s)
- Shiqiang Xiong
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Shaoyang Lin
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Yingru Hu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Weijie Xia
- Department of Plastic & Cosmetic Surgery, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Qianran Wang
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Lijuan Wang
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Tingbing Cao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Yingying Liao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Alexandra Scholze
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark, and Department of Cardiothoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark
| | - Martin Tepel
- Department of Nephrology, Odense University Hospital, Odense, Denmark
- Institute of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Institute of Clinical Research, University of Southern
| | - Zhiming Zhu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Daoyan Liu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, Chongqing Institute of Hypertension, Chongqing, China
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Zhang M, Liu M, Wang W, Ren Z, Wang P, Xue Y, Wang X. The salt sensitivity of Drd4-null mice is associated with the upregulations of sodium transporters in kidneys. Hypertens Res 2024; 47:2144-2156. [PMID: 38778170 DOI: 10.1038/s41440-024-01724-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/01/2024] [Accepted: 04/21/2024] [Indexed: 05/25/2024]
Abstract
To explore the mechanism of the hypertension in dopamine receptor-4 (Drd4) null mice, we determined the salt sensitivity and renal sodium transport proteins in Drd4-/- and Drd4+/+ mice with varied salt diets. On normal NaCl diet (NS), mean arterial pressures (MAP, telemetry) were higher in Drd4-/- than Drd4+/+; Low NaCl diet (LS) tended to decrease MAP in both strains; high NaCl diet (HS) elevated MAP with sodium excretion decreased and pressure-natriuresis curve shifted to right in Drd4-/- relative to Drd4+/+ mice. Drd4-/- mice exhibited increased renal sodium-hydrogen exchanger 3 (NHE3), sodium-potassium-2-chloride cotransporter (NKCC2), sodium-chloride cotransporter (NCC), and outer medullary α-epithelial sodium channel (αENaC) on NS, decreased NKCC2, NCC, αENaC, and αNa+-K+-ATPase on LS, and increased αENaC on HS. NKCC2, NCC, αENaC, and αNa+-K+-ATPase in plasma membrane were greater in Drd4-/- than in Drd4+/+ mice with HS. D4R was expressed in proximal and distal convoluted tubules, thick ascending limbs, and outer medullary collecting ducts and colocalized with NKCC2 and NCC. The phosphorylation of NKCC2 was enhanced but ubiquitination was reduced in the KO mice. There were no differences between the mouse strains in serum aldosterone concentrations and urinary dopamine excretions despite their changes with diets. The mRNA expressions of renal NHE3, NKCC2, NCC, and αENaC on NS were not altered in Drd4-/- mice. Thus, increased protein expressions of NHE3, NKCC2, NCC and αENaC are associated with hypertension in Drd4-/- mice; increased plasma membrane protein expression of NKCC2, NCC, αENaC, and αNa+-K+-ATPase may mediate the salt sensitivity of Drd4-/- mice.
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Affiliation(s)
- Mingzhuo Zhang
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
- Department of Nephrology, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Mingda Liu
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Weiwan Wang
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Zhiyun Ren
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Ping Wang
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Ying Xue
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoyan Wang
- The Core Laboratory for Clinical Research, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China.
- Department of Nephrology, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China.
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Ralph DL, Ha D, Lei H, Priver TS, Smith SD, McFarlin BE, Schwindt S, Pandya D, Koepsell H, Pastor-Soler NM, Edwards A, McDonough AA. Potassium-Alkali-Enriched Diet, Hypertension, and Proteinuria following Uninephrectomy. J Am Soc Nephrol 2024:00001751-990000000-00357. [PMID: 38913441 DOI: 10.1681/asn.0000000000000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 06/10/2024] [Indexed: 06/26/2024] Open
Abstract
Key Points
A K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing Na+ reabsorption.Uninephrectomy-associated proteinuria could be attributed to elevated single-nephron GFR and downregulation of megalin, which reduced fractional protein endocytosis.
Background
Losing or donating a kidney is associated with risks of developing hypertension and albuminuria. Few studies address mechanisms or interventions. We investigate the potential benefits of a K+- alkali–enriched diet and the mechanisms underlying proteinuria.
Methods
Male Sprague Dawley rats were fed either a 2% NaCl+0.95% KCl diet (HNa-LK) or a 0.74% NaCl+3% K+-alkali diet (HK-alk) for 3 weeks before uninephrectomy and then maintained on respective diets for 12 weeks. BP (by tail-cuff), urine, blood, and kidney proteins were analyzed before and after uninephrectomy.
Results
Before uninephrectomy, HK-alk–fed versus HNa-LK–fed rats exhibited similar BPs and plasma [K+], [Na+], but lower proximal (NHE3, sodium bicarbonate cotransporter 1, NaPi2) and higher distal (NCC, ENaC, and pendrin) transporter abundance, a pattern facilitating K+ and HCO3
− secretion. After uninephrectomy, single-nephron GFR increased 50% and Li+ clearance doubled with both diets; in HK-alk versus HNa-LK, the increase in BP was less and ammoniagenesis was lower, abundance of proximal tubule transporters remained lower, ENaC-α fell, and NCCp increased, consistent with K+ conservation. After uninephrectomy, independent of diet, albuminuria increased eight-fold and abundance of endocytic receptors was reduced (megalin by 44%, disabled homolog 2 by 25%–35%) and kidney injury molecule-1 was increased.
Conclusions
The K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing proximal Na+ transporters and increasing K+-alkali secretion. Furthermore, uninephrectomy-associated proteinuria could be attributed, at least in part, to elevated single-nephron GFR coupled with downregulation of megalin, which reduced fractional protein endocytosis and Vmax.
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Affiliation(s)
- Donna L Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Darren Ha
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hillmin Lei
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Taylor S Priver
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Scotti D Smith
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Brandon E McFarlin
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Seth Schwindt
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Drishti Pandya
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hermann Koepsell
- Institute for Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Nuria M Pastor-Soler
- Division of Nephrology, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Aurelie Edwards
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
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Kim BS, Yu MY, Shin J. Effect of low sodium and high potassium diet on lowering blood pressure and cardiovascular events. Clin Hypertens 2024; 30:2. [PMID: 38163867 PMCID: PMC10759559 DOI: 10.1186/s40885-023-00259-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/30/2023] [Indexed: 01/03/2024] Open
Abstract
Incorporating aggressive lifestyle modifications along with antihypertensive medication therapy is a crucial treatment strategy to enhance the control rate of hypertension. Dietary modification is one of the important lifestyle interventions for hypertension, and it has been proven to have a clear effect. Among food ingredients, sodium and potassium have been found to have the strongest association with blood pressure. The blood pressure-lowering effect of a low sodium diet and a high potassium diet has been well established, especially in hypertensive population. A high intake of potassium, a key component of the Dietary Approaches to Stop Hypertension (DASH) diet, has also shown a favorable impact on the risk of cardiovascular events. Additionally, research conducted with robust measurement methods has shown cardiovascular benefits of low-sodium intake. In this review, we aim to discuss the evidence regarding the relationship between the low sodium and high potassium diet and blood pressure and cardiovascular events.
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Affiliation(s)
- Byung Sik Kim
- Division of Cardiology, Department of Internal Medicine, Hanyang University Guri Hospital, Guri, South Korea
| | - Mi-Yeon Yu
- Division of Nephrology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Jinho Shin
- Division of Cardiology, Department of Internal Medicine, Hanyang University Medical Center, Hanyang University College of Medicine, 222, Wangsimni-ro, Sungdong-gu, Seoul, 04763, South Korea.
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McDonough AA, Harris AN, Xiong LI, Layton AT. Sex differences in renal transporters: assessment and functional consequences. Nat Rev Nephrol 2024; 20:21-36. [PMID: 37684523 PMCID: PMC11090267 DOI: 10.1038/s41581-023-00757-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2023] [Indexed: 09/10/2023]
Abstract
Mammalian kidneys are specialized to maintain fluid and electrolyte homeostasis. The epithelial transport processes along the renal tubule that match output to input have long been the subject of experimental and theoretical study. However, emerging data have identified a new dimension of investigation: sex. Like most tissues, the structure and function of the kidney is regulated by sex hormones and chromosomes. Available data demonstrate sex differences in the abundance of kidney solute and electrolyte transporters, establishing that renal tubular organization and operation are distinctly different in females and males. Newer studies have provided insights into the physiological consequences of these sex differences. Computational simulations predict that sex differences in transporter abundance are likely driven to optimize reproduction, enabling adaptive responses to the nutritional requirements of serial pregnancies and lactation - normal life-cycle changes that challenge the ability of renal transporters to maintain fluid and electrolyte homeostasis. Later in life, females may also undergo menopause, which is associated with changes in disease risk. Although numerous knowledge gaps remain, ongoing studies will provide further insights into the sex-specific mechanisms of sodium, potassium, acid-base and volume physiology throughout the life cycle, which may lead to therapeutic opportunities.
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Affiliation(s)
- Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.
| | - Autumn N Harris
- Department of Small Animal Clinical Sciences, University of Florida, College of Veterinary Medicine, Gainesville, FL, USA
| | - Lingyun Ivy Xiong
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA
| | - Anita T Layton
- Departments of Applied Mathematics and Biology, University of Waterloo, Waterloo, Ontario, Canada
- Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, Canada
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
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6
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McDonough AA, Layton AT. Sex differences in renal electrolyte transport. Curr Opin Nephrol Hypertens 2023; 32:467-475. [PMID: 37382185 PMCID: PMC10526720 DOI: 10.1097/mnh.0000000000000909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
PURPOSE OF REVIEW Women experience unique life events, for example, pregnancy and lactation, that challenge renal regulation of electrolyte homeostasis. Recent analyses of nephron organization in female vs. male rodent kidneys, revealed distinct sexual dimorphisms in electrolyte transporter expression, abundance, and activity. This review aims to provide an overview of electrolyte transporters' organization and operation in female compared with the commonly studied male kidney, and the (patho)physiologic consequences of the differences. RECENT FINDINGS When electrolyte transporters are assessed in kidney protein homogenates from both sexes, relative transporter abundance ratios in females/males are less than one along proximal tubule and greater than one post macula densa, which is indicative of a 'downstream shift' in fractional reabsorption of electrolytes in females. This arrangement improves the excretion of a sodium load, challenges potassium homeostasis, and is consistent with the lower blood pressure and greater pressure natriuresis observed in premenopausal women. SUMMARY We summarize recently reported new knowledge about sex differences in renal transporters: abundance and expression along nephron, implications for regulation by Na + , K + and angiotensin II, and mathematical models of female nephron function.
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Affiliation(s)
- Alicia A. McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - Anita T. Layton
- Departments of Applied Mathematics and Biology, University of Waterloo, Waterloo, Ontario, Canada; Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, Canada; School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
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7
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Wang T, Liu T, Xu S, Frindt G, Weinstein AM, Palmer LG. High dietary K + intake inhibits proximal tubule transport. Am J Physiol Renal Physiol 2023; 325:F224-F234. [PMID: 37318989 PMCID: PMC10396284 DOI: 10.1152/ajprenal.00013.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/15/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023] Open
Abstract
The impact of chronic dietary K+ loading on proximal tubule (PT) function was measured using free-flow micropuncture along with measurements of overall kidney function, including urine volume, glomerular filtration rate, and absolute and fractional Na+ and K+ excretion in the rat. Feeding animals a diet with 5% KCl [high K+ (HK)] for 7 days reduced glomerular filtration rate by 29%, increased urine volume by 77%, and increased absolute K+ excretion by 202% compared with rats on a 1% KCl [control K+ (CK)] diet. HK did not change absolute Na+ excretion but significantly increased fraction excretion of Na+ (1.40% vs. 0.64%), indicating that fractional Na+ absorption is reduced by HK. PT reabsorption was assessed using free-flow micropuncture in anesthetized animals. At 80% of the accessible length of the PT, measurements of inulin concentration indicated volume reabsorption of 73% and 54% in CK and HK, respectively. At the same site, fractional PT Na+ reabsorption was 66% in CK animals and 37% in HK animals. Fractional PT K+ reabsorption was 66% in CK and 37% in HK. To assess the role of Na+/H+ exchanger isoform 3 (NHE3) in mediating these changes, we measured NHE3 protein expression in total kidney microsomes as well as surface membranes using Western blots. We found no significant changes in protein in either cell fraction. Expression of the Ser552 phosphorylated form of NHE3 was also similar in CK and HK animals. Reduction in PT transport may facilitate K+ excretion and help balance Na+ excretion by shifting Na+ reabsorption from K+-reabsorbing to K+-secreting nephron segments.NEW & NOTEWORTHY In rats fed a diet rich in K+, proximal tubules reabsorbed less fluid, Na+, and K+ compared with those in animals on a control diet. Glomerular filtration rates also decreased, probably due to glomerulotubular feedback. These reductions may help to maintain balance of the two ions simultaneously by shifting Na+ reabsorption to K+-secreting nephron segments.
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Affiliation(s)
- Tong Wang
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Tommy Liu
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Shuhua Xu
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Gustavo Frindt
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
| | - Alan M Weinstein
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
| | - Lawrence G Palmer
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
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8
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Lombari P, Mallardo M, Petrazzuolo O, Amruthraj Nagoth J, Fiume G, Scanni R, Iervolino A, Damiano S, Coppola A, Borriello M, Ingrosso D, Perna AF, Zacchia M, Trepiccione F, Capasso G. miRNA-23a modulates sodium-hydrogen exchanger 1 expression: studies in medullary thick ascending limb of salt-induced hypertensive rats. Nephrol Dial Transplant 2023; 38:586-598. [PMID: 35921220 DOI: 10.1093/ndt/gfac232] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The kidney is the main organ in the pathophysiology of essential hypertension. Although most bicarbonate reabsorption occurs in the proximal tubule, the medullary thick ascending limb (mTAL) of the nephron also maintains acid-base balance by contributing to 25% of bicarbonate reabsorption. A crucial element in this regulation is the sodium-hydrogen exchanger 1 (NHE1), a ubiquitous membrane protein controlling intracellular pH, where proton extrusion is driven by the inward sodium flux. MicroRNA (miRNA) expression of hypertensive patients significantly differs from that of normotensive subjects. The aim of this study was to determine the functional role of miRNA alterations at the mTAL level. METHODS By miRNA microarray analysis, we identified miRNA expression profiles in isolated mTALs from high sodium intake-induced hypertensive rats (HSD) versus their normotensive counterparts (NSD). In vitro validation was carried out in rat mTAL cells. RESULTS Five miRNAs involved in the onset of salt-sensitive hypertension were identified, including miR-23a, which was bioinformatically predicted to target NHE1 mRNA. Data demonstrated that miRNA-23a is downregulated in the mTAL of HSD rats while NHE1 is upregulated. Consistently, transfection of an miRNA-23a mimic in an mTAL cell line, using a viral vector, resulted in NHE1 downregulation. CONCLUSION NHE1, a protein involved in sodium reabsorption at the mTAL level and blood pressure regulation, is upregulated in our model. This was due to a downregulation of miRNA-23a. Expression levels of this miRNA are influenced by high sodium intake in the mTALs of rats. The downregulation of miRNA-23a in humans affected by essential hypertension corroborate our data and point to the potential role of miRNA-23a in the regulation of mTAL function following high salt intake.
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Affiliation(s)
- Patrizia Lombari
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy.,Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Massimo Mallardo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Oriana Petrazzuolo
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Joseph Amruthraj Nagoth
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Giuseppe Fiume
- Departments of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Roberto Scanni
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Anna Iervolino
- Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Sara Damiano
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - Annapaola Coppola
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Margherita Borriello
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Diego Ingrosso
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Alessandra F Perna
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Miriam Zacchia
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Francesco Trepiccione
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.,Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.,Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
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9
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Inverse Salt Sensitivity of Blood Pressure: Mechanisms and Potential Relevance for Prevention of Cardiovascular Disease. Curr Hypertens Rep 2022; 24:361-374. [PMID: 35708819 DOI: 10.1007/s11906-022-01201-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW To review the etiology of inverse salt sensitivity of blood pressure (BP). RECENT FINDINGS Both high and low sodium (Na+) intake can be associated with increased BP and cardiovascular morbidity and mortality. However, little is known regarding the mechanisms involved in the increase in BP in response to low Na+ intake, a condition termed inverse salt sensitivity of BP, which affects approximately 15% of the adult population. The renal proximal tubule is important in regulating up to 70% of renal Na+ transport. The renin-angiotensin and renal dopaminergic systems play both synergistic and opposing roles in the regulation of Na+ transport in this nephron segment. Clinical studies have demonstrated that individuals express a "personal salt index" (PSI) that marks whether they are salt-resistant, salt-sensitive, or inverse salt-sensitive. Inverse salt sensitivity results in part from genetic polymorphisms in various Na+ regulatory genes leading to a decrease in natriuretic activity and an increase in renal tubular Na+ reabsorption leading to an increase in BP. This article reviews the potential mechanisms of a new pathophysiologic entity, inverse salt sensitivity of BP, which affects approximately 15% of the general adult population.
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Gohar EY, De Miguel C, Obi IE, Daugherty EM, Hyndman KA, Becker BK, Jin C, Sedaka R, Johnston JG, Liu P, Speed JS, Mitchell T, Kriegel AJ, Pollock JS, Pollock DM. Acclimation to a High-Salt Diet Is Sex Dependent. J Am Heart Assoc 2022; 11:e020450. [PMID: 35191321 PMCID: PMC9075092 DOI: 10.1161/jaha.120.020450] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/03/2021] [Indexed: 01/01/2023]
Abstract
Background Premenopausal women are less likely to develop hypertension and salt-related complications than are men, yet the impact of sex on mechanisms regulating Na+ homeostasis during dietary salt challenges is poorly defined. Here, we determined whether female rats have a more efficient capacity to acclimate to increased dietary salt intake challenge. Methods and Results Age-matched male and female Sprague Dawley rats maintained on a normal-salt (NS) diet (0.49% NaCl) were challenged with a 5-day high-salt diet (4.0% NaCl). We assessed serum, urinary, skin, and muscle electrolytes; total body water; and kidney Na+ transporters during the NS and high-salt diet phases. During the 5-day high-salt challenge, natriuresis increased more rapidly in females, whereas serum Na+ and body water concentration increased only in males. To determine if females are primed to handle changes in dietary salt, we asked the question whether the renal endothelin-1 natriuretic system is more active in female rats, compared with males. During the NS diet, female rats had a higher urinary endothelin-1 excretion rate than males. Moreover, Ingenuity Pathway Analysis of RNA sequencing data identified the enrichment of endothelin signaling pathway transcripts in the inner medulla of kidneys from NS-fed female rats compared with male counterparts. Notably, in human subjects who consumed an Na+-controlled diet (3314-3668 mg/day) for 3 days, women had a higher urinary endothelin-1 excretion rate than men, consistent with our findings in NS-fed rats. Conclusions These results suggest that female sex confers a greater ability to maintain Na+ homeostasis during acclimation to dietary Na+ challenges and indicate that the intrarenal endothelin-1 natriuretic pathway is enhanced in women.
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Affiliation(s)
- Eman Y. Gohar
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
- Present address:
Division of Nephrology and HypertensionVanderbilt University Medical CenterNashvilleTN
| | - Carmen De Miguel
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Ijeoma E. Obi
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Elizabeth M. Daugherty
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Kelly A. Hyndman
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Bryan K. Becker
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Chunhua Jin
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Randee Sedaka
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Jermaine G. Johnston
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - Pengyuan Liu
- Department of PhysiologyMedical College of WisconsinMilwaukeeWI
| | - Joshua S. Speed
- Department of PhysiologyUniversity of Mississippi Medical CenterJacksonMS
| | | | | | - Jennifer S. Pollock
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
| | - David M. Pollock
- Section of Cardio‐Renal Physiology & MedicineDivision of NephrologyDepartment of MedicineUniversity of Alabama at BirminghamAL
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11
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Lu A, Pu M, Mo S, Su J, Hu J, Li C, Wang W, Yang T. (Pro)renin Receptor Regulates Phosphate Homeostasis in Rats via Releasing Fibroblast Growth Factor-23. Front Physiol 2022; 13:784521. [PMID: 35222071 PMCID: PMC8874195 DOI: 10.3389/fphys.2022.784521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/14/2022] [Indexed: 11/13/2022] Open
Abstract
Phosphate (Pi) is one of the basic necessities required for sustenance of life and its metabolism largely relies on excretory function of the kidney, a process chiefly under the endocrine control of bone-derived fibroblast growth factor 23 (FGF23). However, knowledge gap exists in understanding the regulatory loop responsible for eliciting phophaturic response to Pi treatment. Here, we reported a novel role of (pro)renin receptor (PRR) in mediating phosphaturic response to Pi treatment via upregulation of FGF23 production. Male Sprague-Dawley rats were pretreated for 5 days via osmotic pump-driven infusion of a PRR antagonist PRO20 or vehicle, and then treated with high Pi (HP) solution as drinking fluid for the last 24 h. PRO20 reduced HP-induced Pi excretion by 42%, accompanied by blunted upregulation of circulating FGF23 and parathyroid hormone (PTH) and downregulation of renal Na/Pi-IIa expression. In cultured osteoblast cells, exposure to HP induced a 1.56-fold increase in FGF23 expression, which was blunted by PRO20 or siRNA against PRR. Together, these results suggest that activation of PRR promotes phosphaturic response through stimulation of FGF23 production and subsequent downregulation of renal Na/Pi-IIa expression.
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Affiliation(s)
- Aihua Lu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Min Pu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shiqi Mo
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jiahui Su
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jiajia Hu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Chunling Li
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Weidong Wang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Tianxin Yang
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, UT, United States
- *Correspondence: Tianxin Yang,
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12
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Torres-Pinzon DL, Ralph DL, Veiras LC, McDonough AA. Sex-specific adaptations to high-salt diet preserve electrolyte homeostasis with distinct sodium transporter profiles. Am J Physiol Cell Physiol 2021; 321:C897-C909. [PMID: 34613843 PMCID: PMC8616593 DOI: 10.1152/ajpcell.00282.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 02/04/2023]
Abstract
Kidneys continuously filter an enormous amount of sodium and adapt kidney Na+ reabsorption to match Na+ intake to maintain circulatory volume and electrolyte homeostasis. Males (M) respond to high-salt (HS) diet by translocating proximal tubule Na+/H+ exchanger isoform 3 (NHE3) to the base of the microvilli, reducing activated forms of the distal NaCl cotransporter (NCC) and epithelial Na+ channel (ENaC). Males (M) and females (F) on normal-salt (NS) diet present sex-specific profiles of "transporters" (cotransporters, channels, pumps, and claudins) along the nephron, e.g., F exhibit 40% lower NHE3 and 200% higher NCC abundance than M. We tested the hypothesis that adaptations to HS diet along the nephron will, likewise, exhibit sexual dimorphisms. C57BL/6J mice were fed for 15 days with 4% NaCl diet (HS) versus 0.26% NaCl diet (NS). On HS, M and F exhibited normal plasma [Na+] and [K+], similar urine volume, Na+, K+, and osmolal excretion rates normalized to body weight. In F, like M, HS lowered abundance of distal NCC, phosphorylated NCC, and cleaved (activated) forms of ENaC. The adaptations associated with achieving electrolyte homeostasis exhibit sex-dependent and independent mechanisms. Sex differences in baseline "transporters" abundance persist during HS diet, yet the fold changes during HS diet (normalized to NS) are similar along the distal nephron and collecting duct. Sex-dependent differences observed along the proximal tubule during HS show that female kidneys adapt differently from patterns reported in males, yet achieve and maintain fluid and electrolyte homeostasis.
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Affiliation(s)
- Diana L Torres-Pinzon
- Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Donna L Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Luciana C Veiras
- Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine of University of Southern California, Los Angeles, California
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13
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Nelson JW, McDonough AA, Xiang Z, Ralph DL, Robertson JA, Giani JF, Bernstein KE, Gurley SB. Local and downstream actions of proximal tubule angiotensin II signaling on Na + transporters in the mouse nephron. Am J Physiol Renal Physiol 2021; 321:F69-F81. [PMID: 34056928 DOI: 10.1152/ajprenal.00014.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The renal nephron consists of a series of distinct cell types that function in concert to maintain fluid and electrolyte balance and blood pressure. The renin-angiotensin system (RAS) is central to Na+ and volume balance. We aimed to determine how loss of angiotensin II signaling in the proximal tubule (PT), which reabsorbs the bulk of filtered Na+ and volume, impacts solute transport throughout the nephron. We hypothesized that PT renin-angiotensin system disruption would not only depress PT Na+ transporters but also impact downstream Na+ transporters. Using a mouse model in which the angiotensin type 1a receptor (AT1aR) is deleted specifically within the PT (AT1aR PTKO), we profiled the abundance of Na+ transporters, channels, and claudins along the nephron. Absence of PT AT1aR signaling was associated with lower abundance of PT transporters (Na+/H+ exchanger isoform 3, electrogenic Na+-bicarbonate cotransporter 1, and claudin 2) as well as lower abundance of downstream transporters (total and phosphorylated Na+-K+-2Cl- cotransporter, medullary Na+-K+-ATPase, phosphorylated NaCl cotransporter, and claudin 7) versus controls. However, transport activities of Na+-K+-2Cl- cotransporter and NaCl cotransporter (assessed with diuretics) were similar between groups in order to maintain electrolyte balance. Together, these results demonstrate the primary impact of angiotensin II regulation on Na+ reabsorption in the PT at baseline and the associated influence on downstream Na+ transporters, highlighting the ability of the nephron to integrate Na+ transport along the nephron to maintain homeostasis.NEW & NOTEWORTHY Our study defines a novel role for proximal tubule angiotensin receptors in regulating the abundance of Na+ transporters throughout the nephron, thereby contributing to the integrated control of fluid balance in vivo.
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Affiliation(s)
- Jonathan W Nelson
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Zhidan Xiang
- Wake Forest University, Winston-Salem, North Carolina
| | - Donna L Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Joshua A Robertson
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Jorge F Giani
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California
| | - Kenneth E Bernstein
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California
| | - Susan B Gurley
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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14
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Duan XP, Wu P, Zhang DD, Gao ZX, Xiao Y, Ray EC, Wang WH, Lin DH. Deletion of Kir5.1 abolishes the effect of high Na + intake on Kir4.1 and Na +-Cl - cotransporter. Am J Physiol Renal Physiol 2021; 320:F1045-F1058. [PMID: 33900854 DOI: 10.1152/ajprenal.00004.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High sodium (HS) intake inhibited epithelial Na+ channel (ENaC) in the aldosterone-sensitive distal nephron and Na+-Cl- cotransporter (NCC) by suppressing basolateral Kir4.1/Kir5.1 in the distal convoluted tubule (DCT), thereby increasing renal Na+ excretion but not affecting K+ excretion. The aim of the present study was to explore whether deletion of Kir5.1 compromises the inhibitory effect of HS on NCC expression/activity and renal K+ excretion. Patch-clamp experiments demonstrated that HS failed to inhibit DCT basolateral K+ channels and did not depolarize K+ current reversal potential of the DCT in Kir5.1 knockout (KO) mice. Moreover, deletion of Kir5.1 not only increased the expression of Kir4.1, phospho-NCC, and total NCC but also abolished the inhibitory effect of HS on the expression of Kir4.1, phospho-NCC, and total NCC and thiazide-induced natriuresis. Also, low sodium-induced stimulation of NCC expression/activity and basolateral K+ channels in the DCT were absent in Kir5.1 KO mice. Deletion of Kir5.1 decreased ENaC currents in the late DCT, and HS further inhibited ENaC activity in Kir5.1 KO mice. Finally, measurement of the basal renal K+ excretion rate with the modified renal clearance method demonstrated that long-term HS inhibited the renal K+ excretion rate and steadily increased plasma K+ levels in Kir5.1 KO mice but not in wild-type mice. We conclude that Kir5.1 plays an important role in mediating the effect of HS intake on basolateral K+ channels in the DCT and NCC activity/expression. Kir5.1 is involved in maintaining renal ability of K+ excretion during HS intake. NEW & NOTEWORTHY Kir5.1 plays an important role in mediating the effect of high sodium intake on basolateral K+ channels in the distal convoluted tubule and Na+-Cl- cotransporter activity/expression.
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Affiliation(s)
- Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Department of Histology and Embryology, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Institute of Hypertension and Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Dan-Dan Zhang
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, People's Republic of China
| | - Zhong-Xiuzi Gao
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Institute of Hypertension and Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Yu Xiao
- Department of Pharmacology, New York Medical College, Valhalla, New York.,Department of Physiology, Qiqihar Medical University, Qiqihar, People's Republic of China
| | - Evan C Ray
- Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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15
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Ralph AF, Grenier C, Costello HM, Stewart K, Ivy JR, Dhaun N, Bailey MA. Activation of the Sympathetic Nervous System Promotes Blood Pressure Salt-Sensitivity in C57BL6/J Mice. Hypertension 2020; 77:158-168. [PMID: 33190558 PMCID: PMC7720873 DOI: 10.1161/hypertensionaha.120.16186] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Global salt intake averages >8 g/person per day, over twice the limit advocated by the American Heart Association. Dietary salt excess leads to hypertension, and this partly mediates its poor health outcomes. In ≈30% of people, the hypertensive response to salt is exaggerated. This salt-sensitivity increases cardiovascular risk. Mechanistic cardiovascular research relies heavily on rodent models and the C57BL6/J mouse is the most widely used reference strain. We examined the effects of high salt intake on blood pressure, renal, and vascular function in the most commonly used and commercially available C57BL6/J mouse strain. Changing from control (0.3% Na+) to high salt (3% Na+) diet increased systolic blood pressure in male mice by ≈10 mm Hg within 4 days of dietary switch. This hypertensive response was maintained over the 3-week study period. Returning to control diet gradually reduced blood pressure back to baseline. High-salt diet caused a rapid and sustained downregulation in mRNA encoding renal NHE3 (sodium-hydrogen-exchanger 3) and EnaC (epithelial sodium channel), although we did not observe a suppression in aldosterone until ≈7 days. During the development of salt-sensitivity, the acute pressure natriuresis relationship was augmented and neutral sodium balance was maintained throughout. High-salt diet increased ex vivo sensitivity of the renal artery to phenylephrine and increased urinary excretion of adrenaline, but not noradrenaline. The acute blood pressure-depressor effect of hexamethonium, a ganglionic blocker, was enhanced by high salt. Salt-sensitivity in commercially sourced C57BL6/J mice is attributable to sympathetic overactivity, increased adrenaline, and enhanced vascular sensitivity to alpha-adrenoreceptor activation and not sodium retention or attenuation of the acute pressure natriuresis response.
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Affiliation(s)
- Ailsa F Ralph
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Celine Grenier
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Hannah M Costello
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Kevin Stewart
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Jessica R Ivy
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Neeraj Dhaun
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Matthew A Bailey
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
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16
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A high salt diet induces tubular damage associated with a pro-inflammatory and pro-fibrotic response in a hypertension-independent manner. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165907. [DOI: 10.1016/j.bbadis.2020.165907] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 12/14/2022]
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17
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Wei KY, Gritter M, Vogt L, de Borst MH, Rotmans JI, Hoorn EJ. Dietary potassium and the kidney: lifesaving physiology. Clin Kidney J 2020; 13:952-968. [PMID: 33391739 PMCID: PMC7769543 DOI: 10.1093/ckj/sfaa157] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Indexed: 02/07/2023] Open
Abstract
Potassium often has a negative connotation in Nephrology as patients with chronic kidney disease (CKD) are prone to develop hyperkalaemia. Approaches to the management of chronic hyperkalaemia include a low potassium diet or potassium binders. Yet, emerging data indicate that dietary potassium may be beneficial for patients with CKD. Epidemiological studies have shown that a higher urinary potassium excretion (as proxy for higher dietary potassium intake) is associated with lower blood pressure (BP) and lower cardiovascular risk, as well as better kidney outcomes. Considering that the composition of our current diet is characterized by a high sodium and low potassium content, increasing dietary potassium may be equally important as reducing sodium. Recent studies have revealed that dietary potassium modulates the activity of the thiazide-sensitive sodium-chloride cotransporter in the distal convoluted tubule (DCT). The DCT acts as a potassium sensor to control the delivery of sodium to the collecting duct, the potassium-secreting portion of the kidney. Physiologically, this allows immediate kaliuresis after a potassium load, and conservation of potassium during potassium deficiency. Clinically, it provides a novel explanation for the inverse relationship between dietary potassium and BP. Moreover, increasing dietary potassium intake can exert BP-independent effects on the kidney by relieving the deleterious effects of a low potassium diet (inflammation, oxidative stress and fibrosis). The aim of this comprehensive review is to link physiology with clinical medicine by proposing that the same mechanisms that allow us to excrete an acute potassium load also protect us from hypertension, cardiovascular disease and CKD.
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Affiliation(s)
- Kuang-Yu Wei
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Division of Nephrology, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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18
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Liu M, Deng M, Luo Q, Dou X, Jia Z. High-Salt Loading Downregulates Nrf2 Expression in a Sodium-Dependent Manner in Renal Collecting Duct Cells. Front Physiol 2020; 10:1565. [PMID: 32038274 PMCID: PMC6985211 DOI: 10.3389/fphys.2019.01565] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/12/2019] [Indexed: 12/11/2022] Open
Abstract
Background High salt intake is associated with both oxidative stress and chronic kidney disease (CKD) progression. Nuclear factor E2-related factor 2 (Nrf2) is a transcriptional factor regulating the antioxidant and detoxifying genes to potently antagonize oxidative stress. This study examined the effect of high salt loading on the expression of Nrf2 in kidney. Methods Mice were treated with acute salt loading, and Nrf2 expression in the kidney was detected by Western blotting and immunostaining. Reactive oxygen species (ROS) levels in the kidney were measured using dihydroethidium (DHE) staining. In vitro, mpkCCD cells were cultured in high osmolality medium by adding sodium chloride (NaCl), sodium gluconate (Na-Glu), choline chloride (Choline-Cl), or mannitol. Then, Nrf2 and its target genes were measured. Results Nrf2 protein in renal cortex and medulla tissue lysates was significantly downregulated after acute salt loading. Immunofluorescence data showed that Nrf2 was mainly located in collecting duct principal cells evidenced by co-staining of Nrf2 with AQP2. Contrasting to the reduced Nrf2 expression, ROS levels in the kidney were significantly increased after salt loading. In vitro, the Nrf2 protein level was downregulated in mpkCCD cells after NaCl treatment for 24 h. Interestingly, sodium gluconate had a similar effect on downregulating Nrf2 expression as NaCl, whereas neither Choline-Cl nor mannitol changed Nrf2 expression. Meanwhile, the mRNA levels of Nrf2 target genes were downregulated by NaCl and/or sodium gluconate, while some of them were also regulated by Choline-Cl, indicating a more complex regulation of these genes under a high salt condition. Finally, we found that the downregulation of Nrf2 caused by NaCl was not affected by N-acetylcysteine (NAC), spironolactone, or NS-398, suggesting other mechanisms mediating Nrf2 downregulation caused by high salt challenge. Conclusion High salt downregulated Nrf2 mainly via a sodium-dependent manner in kidney collecting duct cells, which might contribute to the excessive renal oxidative stress and CKD progression.
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Affiliation(s)
- Mi Liu
- Department of Nephrology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Mokan Deng
- Department of Nephrology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, China
| | - Qimei Luo
- Department of Nephrology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, China
| | - Xianrui Dou
- Department of Nephrology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, China
| | - Zhanjun Jia
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
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19
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Hoorn EJ, Gritter M, Cuevas CA, Fenton RA. Regulation of the Renal NaCl Cotransporter and Its Role in Potassium Homeostasis. Physiol Rev 2020; 100:321-356. [DOI: 10.1152/physrev.00044.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Daily dietary potassium (K+) intake may be as large as the extracellular K+ pool. To avoid acute hyperkalemia, rapid removal of K+ from the extracellular space is essential. This is achieved by translocating K+ into cells and increasing urinary K+ excretion. Emerging data now indicate that the renal thiazide-sensitive NaCl cotransporter (NCC) is critically involved in this homeostatic kaliuretic response. This suggests that the early distal convoluted tubule (DCT) is a K+ sensor that can modify sodium (Na+) delivery to downstream segments to promote or limit K+ secretion. K+ sensing is mediated by the basolateral K+ channels Kir4.1/5.1, a capacity that the DCT likely shares with other nephron segments. Thus, next to K+-induced aldosterone secretion, K+ sensing by renal epithelial cells represents a second feedback mechanism to control K+ balance. NCC’s role in K+ homeostasis has both physiological and pathophysiological implications. During hypovolemia, NCC activation by the renin-angiotensin system stimulates Na+ reabsorption while preventing K+ secretion. Conversely, NCC inactivation by high dietary K+ intake maximizes kaliuresis and limits Na+ retention, despite high aldosterone levels. NCC activation by a low-K+ diet contributes to salt-sensitive hypertension. K+-induced natriuresis through NCC offers a novel explanation for the antihypertensive effects of a high-K+ diet. A possible role for K+ in chronic kidney disease is also emerging, as epidemiological data reveal associations between higher urinary K+ excretion and improved renal outcomes. This comprehensive review will embed these novel insights on NCC regulation into existing concepts of K+ homeostasis in health and disease.
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Affiliation(s)
- Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Catherina A. Cuevas
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Robert A. Fenton
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; and Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Thomson MN, Cuevas CA, Bewarder TM, Dittmayer C, Miller LN, Si J, Cornelius RJ, Su XT, Yang CL, McCormick JA, Hadchouel J, Ellison DH, Bachmann S, Mutig K. WNK bodies cluster WNK4 and SPAK/OSR1 to promote NCC activation in hypokalemia. Am J Physiol Renal Physiol 2019; 318:F216-F228. [PMID: 31736353 DOI: 10.1152/ajprenal.00232.2019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
K+ deficiency stimulates renal salt reuptake via the Na+-Cl- cotransporter (NCC) of the distal convoluted tubule (DCT), thereby reducing K+ losses in downstream nephron segments while increasing NaCl retention and blood pressure. NCC activation is mediated by a kinase cascade involving with no lysine (WNK) kinases upstream of Ste20-related proline-alanine-rich kinase (SPAK) and oxidative stress-responsive kinase-1 (OSR1). In K+ deficiency, WNKs and SPAK/OSR1 concentrate in spherical cytoplasmic domains in the DCT termed "WNK bodies," the significance of which is undetermined. By feeding diets of varying salt and K+ content to mice and using genetically engineered mouse lines, we aimed to clarify whether WNK bodies contribute to WNK-SPAK/OSR1-NCC signaling. Phosphorylated SPAK/OSR1 was present both at the apical membrane and in WNK bodies within 12 h of dietary K+ deprivation, and it was promptly suppressed by K+ loading. In WNK4-deficient mice, however, larger WNK bodies formed, containing unphosphorylated WNK1, SPAK, and OSR1. This suggests that WNK4 is the primary active WNK isoform in WNK bodies and catalyzes SPAK/OSR1 phosphorylation therein. We further examined mice carrying a kidney-specific deletion of the basolateral K+ channel-forming protein Kir4.1, which is required for the DCT to sense plasma K+ concentration. These mice displayed remnant mosaic expression of Kir4.1 in the DCT, and upon K+ deprivation, WNK bodies developed only in Kir4.1-expressing cells. We postulate a model of DCT function in which NCC activity is modulated by plasma K+ concentration via WNK4-SPAK/OSR1 interactions within WNK bodies.
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Affiliation(s)
- Martin N Thomson
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Catherina A Cuevas
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Tim M Bewarder
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Dittmayer
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lauren N Miller
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Jinge Si
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Ryan J Cornelius
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Xiao-Tong Su
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Chao-Ling Yang
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon.,Renal Section, Veterans Affairs Portland Health Care System, Portland, Oregon
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Juliette Hadchouel
- Institut National de la Santé et de la Recherche Médicale, Paris Cardiovascular Research Center, Paris, France
| | - David H Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon.,Renal Section, Veterans Affairs Portland Health Care System, Portland, Oregon
| | - Sebastian Bachmann
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Kerim Mutig
- Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany.,I.M. Sechenov First Moscow State Medical University of the Ministry of Healthcare of the Russian Federation (Sechenovskiy University), Moscow, Russia
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21
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Mun EG, Park JE, Cha YS. Effects of Doenjang, a Traditional Korean Soybean Paste, with High-Salt Diet on Blood Pressure in Sprague-Dawley Rats. Nutrients 2019; 11:nu11112745. [PMID: 31726743 PMCID: PMC6893577 DOI: 10.3390/nu11112745] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/01/2019] [Accepted: 11/07/2019] [Indexed: 02/07/2023] Open
Abstract
Fermented foods in Korea contain a lot of salt. Although salt is reported to exacerbate health trouble, fermented foods have beneficial effects. We hypothesized that doenjang could reduce blood pressure in Sprague-Dawley (SD) rats fed a high-salt diet. Eighteen SD rats were divided into three groups: normal-salt (NS) group, high-salt (HS) group, and high-salt with doenjang (HSD) group. The salinity of doenjang and saltwater was adjusted to 8% using Mohr's method. Blood pressure was significantly reduced in the HSD group compared with the HS group. Water intake and urine excretion volume has significantly increased in the HS group compared with the HSD group. The excreted concentrations of urine sodium, urine potassium, and feces potassium significantly increased in the HSD group compared with the HS and NS groups. Renin level was significantly decreased in the HSD group compared to the other groups. These results indicate that eating traditional salty fermented food is not a direct cause of hypertension, and the intake of doenjang in normal healthy animals improved blood pressure.
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22
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Frame AA, Puleo F, Kim K, Walsh KR, Faudoa E, Hoover RS, Wainford RD. Sympathetic regulation of NCC in norepinephrine-evoked salt-sensitive hypertension in Sprague-Dawley rats. Am J Physiol Renal Physiol 2019; 317:F1623-F1636. [PMID: 31608673 DOI: 10.1152/ajprenal.00264.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Salt sensitivity of blood pressure is characterized by inappropriate sympathoexcitation and renal Na+ reabsorption during high salt intake. In salt-resistant animal models, exogenous norepinephrine (NE) infusion promotes salt-sensitive hypertension and prevents dietary Na+-evoked suppression of the Na+-Cl- cotransporter (NCC). Studies of the adrenergic signaling pathways that modulate NCC activity during NE infusion have yielded conflicting results implicating α1- and/or β-adrenoceptors and a downstream kinase network that phosphorylates and activates NCC, including with no lysine kinases (WNKs), STE20/SPS1-related proline-alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1). In the present study, we used selective adrenoceptor antagonism in NE-infused male Sprague-Dawley rats to investigate the differential roles of α1- and β-adrenoceptors in sympathetically mediated NCC regulation. NE infusion evoked salt-sensitive hypertension and prevented dietary Na+-evoked suppression of NCC mRNA, protein expression, phosphorylation, and in vivo activity. Impaired NCC suppression during high salt intake in NE-infused rats was paralleled by impaired suppression of WNK1 and OxSR1 expression and SPAK/OxSR1 phosphorylation and a failure to increase WNK4 expression. Antagonism of α1-adrenoceptors before high salt intake or after the establishment of salt-sensitive hypertension restored dietary Na+-evoked suppression of NCC, resulted in downregulation of WNK4, SPAK, and OxSR1, and abolished the salt-sensitive component of hypertension. In contrast, β-adrenoceptor antagonism attenuated NE-evoked hypertension independently of dietary Na+ intake and did not restore high salt-evoked suppression of NCC. These findings suggest that a selective, reversible, α1-adenoceptor-gated WNK/SPAK/OxSR1 NE-activated signaling pathway prevents dietary Na+-evoked NCC suppression, promoting the development and maintenance of salt-sensitive hypertension.
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Affiliation(s)
- Alissa A Frame
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Franco Puleo
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Kiyoung Kim
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Kathryn R Walsh
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Elizabeth Faudoa
- College of Arts and Sciences, Boston University, Boston, Massachusetts
| | - Robert S Hoover
- Research Service, Atlanta Veterans Affairs Medical Center, Decatur, Georgia.,Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
| | - Richard D Wainford
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
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23
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Capolongo G, Suzumoto Y, D'Acierno M, Simeoni M, Capasso G, Zacchia M. ERK1,2 Signalling Pathway along the Nephron and Its Role in Acid-base and Electrolytes Balance. Int J Mol Sci 2019; 20:E4153. [PMID: 31450703 PMCID: PMC6747339 DOI: 10.3390/ijms20174153] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/14/2019] [Accepted: 08/22/2019] [Indexed: 12/17/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are intracellular molecules regulating a wide range of cellular functions, including proliferation, differentiation, apoptosis, cytoskeleton remodeling and cytokine production. MAPK activity has been shown in normal kidney, and its over-activation has been demonstrated in several renal diseases. The extracellular signal-regulated protein kinases (ERK 1,2) signalling pathway is the first described MAPK signaling. Intensive investigations have demonstrated that it participates in the regulation of ureteric bud branching, a fundamental process in establishing final nephron number; in addition, it is also involved in the differentiation of the nephrogenic mesenchyme, indicating a key role in mammalian kidney embryonic development. In the present manuscript, we show that ERK1,2 signalling mediates several cellular functions also in mature kidney, describing its role along the nephron and demonstrating whether it contributes to the regulation of ion channels and transporters implicated in acid-base and electrolytes homeostasis.
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Affiliation(s)
- Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
| | | | | | - Mariadelina Simeoni
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
- Biogem Scarl, 83031 Ariano Irpino, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy.
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24
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Crajoinas RO, Polidoro JZ, Girardi ACC. The potential role of myosin motor proteins in mediating the subcellular distribution of NHE3 in the renal proximal tubule. Am J Physiol Renal Physiol 2019; 316:F986-F992. [PMID: 30864843 DOI: 10.1152/ajprenal.00577.2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Isoform 3 of the Na+/H+ exchanger (NHE3) is responsible for the majority of the reabsorption of NaCl, NaHCO3, and, consequently, water in the renal proximal tubule. As such, this transporter plays an essential role in acid-base balance and extracellular fluid volume homeostasis and determining systemic arterial blood pressure levels. NHE3 activity is modulated by a number of mechanisms, including the redistribution of the transporter between the body of the microvilli (where NHE3 is active) and the base of the microvilli (where NHE3 is less active). Although the physiological, pathophysiological, and pharmacological importance of the subcellular distribution of NHE3 has been well established, the exact mechanism whereby NHE3 is translocated along microvilli microdomains of the proximal tubule apical membrane is unknown. Nonmuscle myosin IIA and unconventional myosin VI move cargoes in anterograde and retrograde directions, respectively, and are known to redistribute along with NHE3 in the proximal tubule in response to a variety of natriuretic and antinatriuretic stimuli, including stimulation or inhibition of the renin-angiotensin system, high dietary Na+ intake, and high blood pressure. Therefore, this review aims to discuss the current evidence that suggests a potential role of myosin IIA and myosin VI in mediating the subcellular distribution of NHE3 along the kidney proximal tubule microvilli and their possible contribution in modifying NHE3-mediated Na+ reabsorption under both physiological and pathophysiological conditions.
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Affiliation(s)
- Renato O Crajoinas
- Heart Institute (InCor), University of São Paulo Medical School , São Paulo , Brazil
| | - Juliano Z Polidoro
- Heart Institute (InCor), University of São Paulo Medical School , São Paulo , Brazil
| | - Adriana C C Girardi
- Heart Institute (InCor), University of São Paulo Medical School , São Paulo , Brazil
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25
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Cherezova A, Tomilin V, Buncha V, Zaika O, Ortiz PA, Mei F, Cheng X, Mamenko M, Pochynyuk O. Urinary concentrating defect in mice lacking Epac1 or Epac2. FASEB J 2019; 33:2156-2170. [PMID: 30252533 PMCID: PMC6338637 DOI: 10.1096/fj.201800435r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/27/2018] [Indexed: 11/11/2022]
Abstract
cAMP is a universal second messenger regulating a plethora of processes in the kidney. Two downstream effectors of cAMP are PKA and exchange protein directly activated by cAMP (Epac), which, unlike PKA, is often linked to elevation of [Ca2+]i. While both Epac isoforms (Epac1 and Epac2) are expressed along the nephron, their relevance in the kidney remains obscure. We combined ratiometric calcium imaging with quantitative immunoblotting, immunofluorescent confocal microscopy, and balance studies in mice lacking Epac1 or Epac2 to determine the role of Epac in renal water-solute handling. Epac1-/- and Epac2-/- mice developed polyuria despite elevated arginine vasopressin levels. We did not detect major deficiencies in arginine vasopressin [Ca2+]i signaling in split-opened collecting ducts or decreases in aquaporin water channel type 2 levels. Instead, sodium-hydrogen exchanger type 3 levels in the proximal tubule were dramatically reduced in Epac1-/- and Epac2-/- mice. Water deprivation revealed persisting polyuria, impaired urinary concentration ability, and augmented urinary excretion of Na+ and urea in both mutant mice. In summary, we report a nonredundant contribution of Epac isoforms to renal function. Deletion of Epac1 and Epac2 decreases sodium-hydrogen exchanger type 3 expression in the proximal tubule, leading to polyuria and osmotic diuresis.-Cherezova, A., Tomilin, V., Buncha, V., Zaika, O., Ortiz, P. A., Mei, F., Cheng, X., Mamenko, M., Pochynyuk, O. Urinary concentrating defect in mice lacking Epac1 or Epac2.
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Affiliation(s)
- Alena Cherezova
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Vadym Buncha
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleg Zaika
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Pablo A. Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Fang Mei
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Mykola Mamenko
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
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26
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Packer M. Role of the sodium-hydrogen exchanger in mediating the renal effects of drugs commonly used in the treatment of type 2 diabetes. Diabetes Obes Metab 2018; 20:800-811. [PMID: 29227582 DOI: 10.1111/dom.13191] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 12/07/2017] [Indexed: 01/19/2023]
Abstract
Diabetes is characterized by increased activity of the sodium-hydrogen exchanger (NHE) in the glomerulus and renal tubules, which contributes importantly to the development of nephropathy. Despite the established role played by the exchanger in experimental studies, it has not been specifically targeted by those seeking to develop novel pharmacological treatments for diabetes. This review demonstrates that many existing drugs that are commonly prescribed to patients with diabetes act on the NHE1 and NHE3 isoforms in the kidney. This action may explain their effects on sodium excretion, albuminuria and the progressive decline of glomerular function in clinical trials; these responses cannot be readily explained by the influence of these drugs on blood glucose. Agents that may affect the kidney in diabetes by virtue of an action on NHE include: (1) insulin and insulin sensitizers; (2) incretin-based agents; (3) sodium-glucose cotransporter 2 inhibitors; (4) antagonists of the renin-angiotensin system (angiotensin converting-enzyme inhibitors, angiotensin receptor blockers and angiotensin receptor neprilysin inhibitors); and (5) inhibitors of aldosterone action and cholesterol synthesis (spironolactone, amiloride and statins). The renal effects of each of these drug classes in patients with type 2 diabetes may be related to a single shared biological mechanism.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas
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27
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Udwan K, Abed A, Roth I, Dizin E, Maillard M, Bettoni C, Loffing J, Wagner CA, Edwards A, Feraille E. Dietary sodium induces a redistribution of the tubular metabolic workload. J Physiol 2017; 595:6905-6922. [PMID: 28940314 PMCID: PMC5685825 DOI: 10.1113/jp274927] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/11/2017] [Indexed: 01/11/2023] Open
Abstract
Key points Body Na+ content is tightly controlled by regulated urinary Na+ excretion. The intrarenal mechanisms mediating adaptation to variations in dietary Na+ intake are incompletely characterized. We confirmed and expanded observations in mice that variations in dietary Na+ intake do not alter the glomerular filtration rate but alter the total and cell‐surface expression of major Na+ transporters all along the kidney tubule. Low dietary Na+ intake increased Na+ reabsorption in the proximal tubule and decreased it in more distal kidney tubule segments. High dietary Na+ intake decreased Na+ reabsorption in the proximal tubule and increased it in distal segments with lower energetic efficiency. The abundance of apical transporters and Na+ delivery are the main determinants of Na+ reabsorption along the kidney tubule. Tubular O2 consumption and the efficiency of sodium reabsorption are dependent on sodium diet.
Abstract Na+ excretion by the kidney varies according to dietary Na+ intake. We undertook a systematic study of the effects of dietary salt intake on glomerular filtration rate (GFR) and tubular Na+ reabsorption. We examined the renal adaptive response in mice subjected to 7 days of a low sodium diet (LSD) containing 0.01% Na+, a normal sodium diet (NSD) containing 0.18% Na+ and a moderately high sodium diet (HSD) containing 1.25% Na+. As expected, LSD did not alter measured GFR and increased the abundance of total and cell‐surface NHE3, NKCC2, NCC, α‐ENaC and cleaved γ‐ENaC compared to NSD. Mathematical modelling predicted that tubular Na+ reabsorption increased in the proximal tubule but decreased in the distal nephron because of diminished Na+ delivery. This prediction was confirmed by the natriuretic response to diuretics targeting the thick ascending limb, the distal convoluted tubule or the collecting system. On the other hand, HSD did not alter measured GFR but decreased the abundance of the aforementioned transporters compared to NSD. Mathematical modelling predicted that tubular Na+ reabsorption decreased in the proximal tubule but increased in distal segments with lower transport efficiency with respect to O2 consumption. This prediction was confirmed by the natriuretic response to diuretics. The activity of the metabolic sensor adenosine monophosphate‐activated protein kinase (AMPK) was related to the changes in tubular Na+ reabsorption. Our data show that fractional Na+ reabsorption is distributed differently according to dietary Na+ intake and induces changes in tubular O2 consumption and sodium transport efficiency. Body Na+ content is tightly controlled by regulated urinary Na+ excretion. The intrarenal mechanisms mediating adaptation to variations in dietary Na+ intake are incompletely characterized. We confirmed and expanded observations in mice that variations in dietary Na+ intake do not alter the glomerular filtration rate but alter the total and cell‐surface expression of major Na+ transporters all along the kidney tubule. Low dietary Na+ intake increased Na+ reabsorption in the proximal tubule and decreased it in more distal kidney tubule segments. High dietary Na+ intake decreased Na+ reabsorption in the proximal tubule and increased it in distal segments with lower energetic efficiency. The abundance of apical transporters and Na+ delivery are the main determinants of Na+ reabsorption along the kidney tubule. Tubular O2 consumption and the efficiency of sodium reabsorption are dependent on sodium diet.
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Affiliation(s)
- Khalil Udwan
- Department of Cellular Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel-Servet, CH-1211, Geneva 4, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
| | - Ahmed Abed
- Department of Cellular Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel-Servet, CH-1211, Geneva 4, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
| | - Isabelle Roth
- Department of Cellular Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel-Servet, CH-1211, Geneva 4, Switzerland
| | - Eva Dizin
- Department of Cellular Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel-Servet, CH-1211, Geneva 4, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
| | - Marc Maillard
- Centre hospitalier universitaire Vaudois, Service de néphrologie, CH-1011, Lausanne, Switzerland
| | - Carla Bettoni
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Johannes Loffing
- Institute of Anatomy, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
| | - Aurélie Edwards
- Centre de Recherche des Cordeliers, INSERM UMRS1138 and CNRS ERL8228, 15 rue de l'Ecole de Médecine, F-75006, Paris, France.,Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Eric Feraille
- Department of Cellular Physiology and Metabolism, University of Geneva, CMU, 1 Rue Michel-Servet, CH-1211, Geneva 4, Switzerland.,National Centre of Competence in Research, NCCRKidney, CH, Switzerland
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28
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Rojas M, Díaz P, León P, Gonzalez AA, González M, Barrientos V, Pestov NB, Alzamora R, Michea L. Mineralocorticoids modulate the expression of the β-3 subunit of the Na +, K +-ATPase in the renal collecting duct. Channels (Austin) 2017. [PMID: 28636485 DOI: 10.1080/19336950.2017.1344800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Renal sodium reabsorption depends on the activity of the Na+,K+-ATPase α/β heterodimer. Four α (α1-4) and 3 β (β1-3) subunit isoforms have been described. It is accepted that renal tubule cells express α1/β1 dimers. Aldosterone stimulates Na+,K+-ATPase activity and may modulate α1/β1 expression. However, some studies suggest the presence of β3 in the kidney. We hypothesized that the β3 isoform of the Na+,K+-ATPase is expressed in tubular cells of the distal nephron, and modulated by mineralocorticoids. We found that β3 is highly expressed in collecting duct of rodents, and that mineralocorticoids decreased the expression of β3. Thus, we describe a novel molecular mechanism of sodium pump modulation that may contribute to the effects of mineralocorticoids on sodium reabsorption.
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Affiliation(s)
- Macarena Rojas
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| | - Pablo Díaz
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| | - Pablo León
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| | - Alexis A Gonzalez
- b Instituto de Química, Pontificia Universidad Católica de Valparaíso , Valparaíso , Chile
| | - Magdalena González
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| | - Víctor Barrientos
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| | - Nikolay B Pestov
- c Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry , Moscow , Russia.,d Department of Physiology and Pharmacology and Center for Diabetes and Endocrine Research , University of Toledo College of Medicine , Toledo , OH , USA
| | - Rodrigo Alzamora
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile.,e Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD) , Santiago , Chile
| | - Luis Michea
- a Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile.,f Millennium Institute on Immunology and Immunotherapy , Santiago , Chile
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29
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Fenton RA, Poulsen SB, de la Mora Chavez S, Soleimani M, Dominguez Rieg JA, Rieg T. Renal tubular NHE3 is required in the maintenance of water and sodium chloride homeostasis. Kidney Int 2017; 92:397-414. [PMID: 28385297 DOI: 10.1016/j.kint.2017.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 01/25/2017] [Accepted: 02/02/2017] [Indexed: 11/30/2022]
Abstract
The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it facilitates sodium (re)absorption and proton secretion. The importance of NHE3 in the kidney for sodium chloride homeostasis, relative to the intestine, is unknown. Constitutive tubule-specific NHE3 knockout mice (NHE3loxloxCre) did not show significant differences compared to control mice in body weight, blood pH or bicarbonate and plasma sodium, potassium, or aldosterone levels. Fluid intake, urinary flow rate, urinary sodium/creatinine, and pH were significantly elevated in NHE3loxloxCre mice, while urine osmolality and GFR were significantly lower. Water deprivation revealed a small urinary concentrating defect in NHE3loxloxCre mice on a control diet, exaggerated on low sodium chloride. Ten days of low or high sodium chloride diet did not affect plasma sodium in control mice; however, NHE3loxloxCre mice were susceptible to low sodium chloride (about -4 mM) or high sodium chloride intake (about +2 mM) versus baseline, effects without differences in plasma aldosterone between groups. Blood pressure was significantly lower in NHE3loxloxCre mice and was sodium chloride sensitive. In control mice, the expression of the sodium/phosphate co-transporter Npt2c was sodium chloride sensitive. However, lack of tubular NHE3 blunted Npt2c expression. Alterations in the abundances of sodium/chloride cotransporter and its phosphorylation at threonine 58 as well as the abundances of the α-subunit of the epithelial sodium channel, and its cleaved form, were also apparent in NHE3loxloxCre mice. Thus, renal NHE3 is required to maintain blood pressure and steady-state plasma sodium levels when dietary sodium chloride intake is modified.
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Affiliation(s)
- Robert A Fenton
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren B Poulsen
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark; VA San Diego Healthcare System, San Diego, California, USA
| | | | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, USA
| | - Jessica A Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA.
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Giani JF, Eriguchi M, Bernstein EA, Katsumata M, Shen XZ, Li L, McDonough AA, Fuchs S, Bernstein KE, Gonzalez-Villalobos RA. Renal tubular angiotensin converting enzyme is responsible for nitro-L-arginine methyl ester (L-NAME)-induced salt sensitivity. Kidney Int 2016; 91:856-867. [PMID: 27988209 DOI: 10.1016/j.kint.2016.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 09/29/2016] [Accepted: 10/06/2016] [Indexed: 01/13/2023]
Abstract
Renal parenchymal injury predisposes to salt-sensitive hypertension, but how this occurs is not known. Here we tested whether renal tubular angiotensin converting enzyme (ACE), the main site of kidney ACE expression, is central to the development of salt sensitivity in this setting. Two mouse models were used: it-ACE mice in which ACE expression is selectively eliminated from renal tubular epithelial cells; and ACE 3/9 mice, a compound heterozygous mouse model that makes ACE only in renal tubular epithelium from the ACE 9 allele, and in liver hepatocytes from the ACE 3 allele. Salt sensitivity was induced using a post L-NAME salt challenge. While both wild-type and ACE 3/9 mice developed arterial hypertension following three weeks of high salt administration, it-ACE mice remained normotensive with low levels of renal angiotensin II. These mice displayed increased sodium excretion, lower sodium accumulation, and an exaggerated reduction in distal sodium transporters. Thus, in mice with renal injury induced by L-NAME pretreatment, renal tubular epithelial ACE, and not ACE expression by renal endothelium, lung, brain, or plasma, is essential for renal angiotensin II accumulation and salt-sensitive hypertension.
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Affiliation(s)
- Jorge F Giani
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Masahiro Eriguchi
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Ellen A Bernstein
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Makoto Katsumata
- Cedars-Sinai Animal Models Core, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Xiao Z Shen
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Liang Li
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Alicia A McDonough
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Sebastien Fuchs
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Kenneth E Bernstein
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Romer A Gonzalez-Villalobos
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA; CVMET Research Unit, Pfizer, Inc., Cambridge, Massachusetts, USA.
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Chen Y, Wu S, Tian Y, Kong J. Phosphorylation and subcellular localization of Na+/H+ exchanger isoform 3 (NHE3) are associated with altered gallbladder absorptive function after formation of cholesterol gallstones. J Physiol Biochem 2016; 73:133-139. [DOI: 10.1007/s13105-016-0533-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 10/21/2016] [Indexed: 01/14/2023]
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McDonough AA. ISN Forefronts Symposium 2015: Maintaining Balance Under Pressure-Hypertension and the Proximal Tubule. Kidney Int Rep 2016; 1:166-176. [PMID: 27840855 PMCID: PMC5102061 DOI: 10.1016/j.ekir.2016.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Renal control of effective circulating volume (ECV) is key for circulatory performance. When renal sodium excretion is inadequate, blood pressure rises and serves as a homeostatic signal to drive natriuresis to re-establish ECV. Recognizing that hypertension involves both renal and vascular dysfunction, this report concerns proximal tubule sodium hydrogen exchanger 3 (NHE3) regulation during acute and chronic hypertension. NHE3 is distributed in tall microvilli (MV) in the proximal tubule, where it reabsorbs a significant fraction of the filtered sodium. NHE3 redistributes, in the plane of the MV membrane, between the MV body, where NHE3 is active, and the MV base, where NHE3 is less active. A high-salt diet and acute hypertension both retract NHE3 to the base and reduce proximal tubule sodium reabsorption independent of a change in abundance. The renin angiotensin system provokes NHE3 redistribution independent of blood pressure: The angiotensin-converting enzyme (ACE) inhibitor captopril redistributes NHE3 to the base and subsequent angiotensin II (AngII) infusion returns NHE3 to the body of the MV and restores reabsorption. Chronic AngII infusion presents simultaneous AngII stimulation and hypertension; that is, NHE3 remains in the body of the MV, due to the high local AngII level and inflammation, and exhibits a compensatory decrease in abundance driven by the hypertension. Genetically modified mice with blunted hypertensive responses to chronic AngII infusion (due to lack of the proximal tubule AngII receptors interleukin-17A or interferon-γ expression) exhibit reduced local AngII accumulation and inflammation and larger decreases in NHE3 abundance, which improves the pressure natriuresis response and reduces the need for elevated blood pressure to facilitate circulating volume balance.
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Affiliation(s)
- Alicia A McDonough
- Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California
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Shah PT, Martin R, Yan Y, Shapiro JI, Liu J. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis. Front Physiol 2016; 7:256. [PMID: 27445847 PMCID: PMC4923243 DOI: 10.3389/fphys.2016.00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/11/2016] [Indexed: 01/01/2023] Open
Abstract
Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).
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Affiliation(s)
- Preeya T Shah
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Rebecca Martin
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
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Walsh KR, Kuwabara JT, Shim JW, Wainford RD. Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats. Am J Physiol Regul Integr Comp Physiol 2015; 310:R115-24. [PMID: 26608659 DOI: 10.1152/ajpregu.00514.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 11/11/2015] [Indexed: 01/11/2023]
Abstract
Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P < 0.05]. In these salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P < 0.05; NE+NS: 11.1 ± 1.1; NE+HS: 10.8 ± 0.4). NE infusion did not alter NCC expression in animals maintained on NS; however, dietary sodium-evoked suppression of NCC expression was prevented in animals challenged with NE. Chronic NCC antagonism abolished the salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension.
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Affiliation(s)
- Kathryn R Walsh
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Jill T Kuwabara
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Joon W Shim
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
| | - Richard D Wainford
- Department of Pharmacology and Experimental Therapeutics and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
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Abstract
The H(+) concentration in human blood is kept within very narrow limits, ~40 nmol/L, despite the fact that dietary metabolism generates acid and base loads that are added to the systemic circulation throughout the life of mammals. One of the primary functions of the kidney is to maintain the constancy of systemic acid-base chemistry. The kidney has evolved the capacity to regulate blood acidity by performing three key functions: (i) reabsorb HCO3(-) that is filtered through the glomeruli to prevent its excretion in the urine; (ii) generate a sufficient quantity of new HCO3(-) to compensate for the loss of HCO3(-) resulting from dietary metabolic H(+) loads and loss of HCO3(-) in the urea cycle; and (iii) excrete HCO3(-) (or metabolizable organic anions) following a systemic base load. The ability of the kidney to perform these functions requires that various cell types throughout the nephron respond to changes in acid-base chemistry by modulating specific ion transport and/or metabolic processes in a coordinated fashion such that the urine and renal vein chemistry is altered appropriately. The purpose of the article is to provide the interested reader with a broad review of a field that began historically ~60 years ago with whole animal studies, and has evolved to where we are currently addressing questions related to kidney acid-base regulation at the single protein structure/function level.
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Affiliation(s)
- Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine, Los Angeles, CA; Brain Research Institute, UCLA, Los Angeles, CA
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36
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McDonough AA, Nguyen MTX. Maintaining Balance Under Pressure: Integrated Regulation of Renal Transporters During Hypertension. Hypertension 2015; 66:450-5. [PMID: 26101347 DOI: 10.1161/hypertensionaha.115.04593] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 05/27/2015] [Indexed: 01/11/2023]
Affiliation(s)
- Alicia A McDonough
- From the Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles (A.A.M., M.T.X.N.).
| | - Mien T X Nguyen
- From the Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles (A.A.M., M.T.X.N.)
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Feng X, Zhang Y, Shao N, Wang Y, Zhuang Z, Wu P, Lee MJ, Liu Y, Wang X, Zhuang J, Delpire E, Gu D, Cai H. Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway. Am J Physiol Renal Physiol 2015; 308:F1119-27. [PMID: 25761881 DOI: 10.1152/ajprenal.00543.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 03/09/2015] [Indexed: 12/15/2022] Open
Abstract
Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs.
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Affiliation(s)
- Xiuyan Feng
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Yiqian Zhang
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China; Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Ningjun Shao
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China
| | - Yanhui Wang
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Renal Division, the First Affiliated Hospital, Wenzhou Medical University, Zhejiang, China
| | - Zhizhi Zhuang
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China; Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Ping Wu
- Renal Division, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Matthew J Lee
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Yingli Liu
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Xiaonan Wang
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Jieqiu Zhuang
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Dingying Gu
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China
| | - Hui Cai
- Renal Division, the Second Affiliated Hospital, Wenzhou Medical University, Zhejiang, China; Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Section of Nephrology, Atlanta Veterans Administration Medical Center, Decatur, Georgia
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38
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Chen Y, Kong J, Wu S. Cholesterol gallstone disease: focusing on the role of gallbladder. J Transl Med 2015; 95:124-31. [PMID: 25502177 DOI: 10.1038/labinvest.2014.140] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/11/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023] Open
Abstract
Gallstone disease (GSD) is one of the most common biliary tract diseases worldwide in which both genetic and environmental factors have roles in its pathogenesis. Biliary cholesterol supersaturation from metabolic defects in the liver is traditionally seen as the main pathogenic factor. Recently, there have been renewed investigative interests in the downstream events that occur in gallbladder lithogenesis. This article focuses on the role of the gallbladder in the pathogenesis of cholesterol GSD (CGD). Various conditions affecting the crystallization process are discussed, such as gallbladder motility, concentrating function, lipid transport, and an imbalance between pro-nucleating and nucleation inhibiting proteins.
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Affiliation(s)
- Yongsheng Chen
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jing Kong
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Shuodong Wu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China
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Chen Y, Kong J, Wu S. Expression and subcellular localization of NHE₃ in the human gallbladder epithelium. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:8791-8796. [PMID: 25674247 PMCID: PMC4314048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/26/2014] [Indexed: 06/04/2023]
Abstract
BACKGROUND Enhanced gallbladder concentrating function is an important factor for the pathogenesis of cholesterol gallstone disease (CGD), but the mechanism is unknown. Potential candidates for regulation of gallbladder ion absorption are suggested to be Na(+)/H(+) exchanger isoform 3 (NHE3). In this study, we investigated the expression and subcellular localization of NHE3 in both acalculous and calculous human gallbladders. METHODS Adult human gallbladder tissue was obtained from 23 patients (7 men, 16 women) who had undergone cholecystectomy. The patients were divided into two groups: Group A (acalculous group) and Group B (calculous group). Gene expression of NHE3 was quantitatively estimated by real-time PCR. Protein expression was studied by Western blotting assays. Furthermore, expression of immunoreactive NHE3 was investigated by immunohistochemistry. RESULTS There was no significant difference in the NHE3 mRNA expression between calculous and acalculous human gallbladders. NHE3 protein expression in gallbladders from patients with cholelithiasis is increased compared to those without gallstones. Immunohistochemistry studies prove that NHE3 is located both on the apical plasma membrane and in the intracellular pool in human GBECs. CONCLUSIONS NHE3 may play a role in the pathogenesis of human CGD. Additional studies are required to further delineate the underlying mechanisms.
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Affiliation(s)
- Yongsheng Chen
- Department of General Surgery, Shengjing Hospital of China Medical University Shenyang, China
| | - Jing Kong
- Department of General Surgery, Shengjing Hospital of China Medical University Shenyang, China
| | - Shuodong Wu
- Department of General Surgery, Shengjing Hospital of China Medical University Shenyang, China
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Chen T, Hubbard A, Murtazina R, Price J, Yang J, Cha B, Sarker R, Donowitz M. Myosin VI mediates the movement of NHE3 down the microvillus in intestinal epithelial cells. J Cell Sci 2014; 127:3535-45. [PMID: 24928903 PMCID: PMC4132392 DOI: 10.1242/jcs.149930] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 05/13/2014] [Indexed: 12/27/2022] Open
Abstract
The intestinal brush border Na(+)/H(+) exchanger NHE3 is tightly regulated through changes in its endocytosis and exocytosis. Myosin VI, a minus-end-directed actin motor, has been implicated in endocytosis at the inter-microvillar cleft and during vesicle remodeling in the terminal web. Here, we asked whether myosin VI also regulates NHE3 movement down the microvillus. The basal NHE3 activity and its surface amount, determined by fluorometry of the ratiometric pH indicator BCECF and biotinylation assays, respectively, were increased in myosin-VI-knockdown (KD) Caco-2/Bbe cells. Carbachol (CCH) and forskolin (FSK) stimulated NHE3 endocytosis in control but not in myosin VI KD cells. Importantly, immunoelectron microscopy results showed that NHE3 was preferentially localized in the basal half of control microvilli but in the distal half in myosin VI KD cells. Treatment with dynasore duplicated some aspects of myosin VI KD: it increased basal surface NHE3 activity and prevented FSK-induced NHE3 endocytosis. However, NHE3 had an intermediate distribution along the microvillus (between that in myosin VI KD and untreated cells) in dynasore-treated cells. We conclude that myosin VI is required for basal and stimulated endocytosis of NHE3 in intestinal cells, and suggest that myosin VI also moves NHE3 down the microvillus.
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Affiliation(s)
- Tiane Chen
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ann Hubbard
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rakhilya Murtazina
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jennifer Price
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Gastroenterology, University of California, School of Medicine, San Francisco, CA 94143, USA
| | - Jianbo Yang
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Boyoung Cha
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rafiquel Sarker
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Departments of Medicine and Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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41
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Crajoinas RO, Pessoa TD, Rodrigues MV, Malnic G, Girardi ACC. Changes in the activity and expression of protein phosphatase-1 accompany the differential regulation of NHE3 before and after the onset of hypertension in spontaneously hypertensive rats. Acta Physiol (Oxf) 2014; 211:395-408. [PMID: 24666699 DOI: 10.1111/apha.12288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 11/18/2013] [Accepted: 03/18/2014] [Indexed: 12/14/2022]
Abstract
AIM The Na(+) /H(+) exchanger NHE3 activity decreases in the proximal tubule of spontaneously hypertensive rats (SHRs) as blood pressure increases, and this reduction is correlated with higher NHE3 phosphorylation levels at the PKA consensus site serine 552. This study tested the hypothesis that this lowered NHE3 activity is associated with an increase in PKA activity and expression, and/or a decrease in protein phosphatase-1 (PP1) activity and expression. METHODS Proximal tubule NHE3 activity was measured as the rate of bicarbonate reabsorption by stationary microperfusion. NHE3 phosphorylation and protein expression were determined by immunoblotting. PKA and PP1 activities were determined using specific substrates under optimal enzymatic conditions. RESULTS The PKA activator, 6-MB-cAMP, increased the phosphorylation levels of NHE3 at serine 552 in the renal cortex; this increase happens to a much greater extent in young pre-hypertensive SHRs (Y-SHRs) compared to adult SHRs with established hypertension (A-SHRs). Likewise, the inhibitory effect of 6-MB-cAMP on NHE3 transport activity was much more pronounced in the proximal tubules of Y-SHRs than in those of A-SHRs. Renal cortical activity of PKA was not significantly different between Y-SHRs and A-SHRs. On the other hand, Y-SHRs exhibited higher protein phosphatase 1 (PP1) activity, and their expression of the PP1 catalytic subunit PP1α in the renal cortex was also higher than in A-SHRs. CONCLUSION Collectively, these results support the idea that the lower NHE3 transport activity and higher phosphorylation occurring after the development of hypertension in SHRs are due, at least in part, to reduced PP1-mediated dephosphorylation of NHE3 at serine 552.
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Affiliation(s)
- R. O. Crajoinas
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
| | - T. D. Pessoa
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - M. V. Rodrigues
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
| | - G. Malnic
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - A. C. C. Girardi
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
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Nagami GT, Plumer AK, Beyda RM, Schachter O. Effects of acid challenges on type 2 angiotensin II receptor-sensitive ammonia production by the proximal tubule. Am J Physiol Renal Physiol 2014; 307:F53-7. [PMID: 24829505 DOI: 10.1152/ajprenal.00466.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Angiotensin II (ANG II) acting through its type 1 (AT1) receptor stimulates total ammonia (tNH3) production by the proximal tubule. The present studies explored the role of ANG II type 2 (AT2) receptors in modulating the stimulatory effects of ANG II on tNH3 production. Mouse S2 proximal tubule segments derived from 18-h and 7-day acid-loaded mice, and non-acid-loaded controls were dissected and microperfused in vitro. Adding ANG II to the luminal perfusion solution resulted in different increments in tNH3 production rates in tubules derived from 18-h vs. 7-day acid-loaded mice such that the increase in tNH3 production with ANG II was higher in tubules derived from 18-h acid-loaded mice compared with those derived from control and 7-day acid-loaded mice. Adding the AT2 receptor blocker PD123319 with ANG II increased ANG II-stimulated tNH3 production in S2 segments from control and 7-day acid-loaded mice but not in those from 18-h acid-loaded mice, and this increased effect of PD123319 was associated with higher AT2 receptor protein levels in brush-border membranes. Studies in cultured proximal tubule cells demonstrated that 2-h exposure to pH 7.0 reduced the modulating effect of PD123319 on ANG II-simulated tNH3 production and reduced cell surface AT2 receptor levels. We concluded that AT2 receptors reduce the stimulatory effect of ANG II on proximal tubule tNH3 production and that the time-dependent impact of AT2 receptor blockade on the ANG II-stimulated tNH3 production corresponded to time-dependent changes in AT2 receptor cell surface expression in the proximal tubule.
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Affiliation(s)
- Glenn T Nagami
- Nephrology Section 111L, Veterans Affairs Greater Los Angeles Healthcare System, and Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Alexandria K Plumer
- Nephrology Section 111L, Veterans Affairs Greater Los Angeles Healthcare System, and Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Raymond M Beyda
- Nephrology Section 111L, Veterans Affairs Greater Los Angeles Healthcare System, and Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Oran Schachter
- Nephrology Section 111L, Veterans Affairs Greater Los Angeles Healthcare System, and Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, California
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Moes AD, van der Lubbe N, Zietse R, Loffing J, Hoorn EJ. The sodium chloride cotransporter SLC12A3: new roles in sodium, potassium, and blood pressure regulation. Pflugers Arch 2013; 466:107-18. [PMID: 24310820 DOI: 10.1007/s00424-013-1407-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/14/2022]
Abstract
SLC12A3 encodes the thiazide-sensitive sodium chloride cotransporter (NCC), which is primarily expressed in the kidney, but also in intestine and bone. In the kidney, NCC is located in the apical plasma membrane of epithelial cells in the distal convoluted tubule. Although NCC reabsorbs only 5 to 10% of filtered sodium, it is important for the fine-tuning of renal sodium excretion in response to various hormonal and non-hormonal stimuli. Several new roles for NCC in the regulation of sodium, potassium, and blood pressure have been unraveled recently. For example, the recent discoveries that NCC is activated by angiotensin II but inhibited by dietary potassium shed light on how the kidney handles sodium during hypovolemia (high angiotensin II) and hyperkalemia. The additive effect of angiotensin II and aldosterone maximizes sodium reabsorption during hypovolemia, whereas the inhibitory effect of potassium on NCC increases delivery of sodium to the potassium-secreting portion of the nephron. In addition, great steps have been made in unraveling the molecular machinery that controls NCC. This complex network consists of kinases and ubiquitinases, including WNKs, SGK1, SPAK, Nedd4-2, Cullin-3, and Kelch-like 3. The pathophysiological significance of this network is illustrated by the fact that modification of each individual protein in the network changes NCC activity and results in salt-dependent hypotension or hypertension. This review aims to summarize these new insights in an integrated manner while identifying unanswered questions.
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Affiliation(s)
- Arthur D Moes
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, Room H-438, 3000 CA, Rotterdam, The Netherlands
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Christensen EI, Wagner CA, Kaissling B. Uriniferous tubule: structural and functional organization. Compr Physiol 2013; 2:805-61. [PMID: 23961562 DOI: 10.1002/cphy.c100073] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The uriniferous tubule is divided into the proximal tubule, the intermediate (thin) tubule, the distal tubule and the collecting duct. The present chapter is based on the chapters by Maunsbach and Christensen on the proximal tubule, and by Kaissling and Kriz on the distal tubule and collecting duct in the 1992 edition of the Handbook of Physiology, Renal Physiology. It describes the fine structure (light and electron microscopy) of the entire mammalian uriniferous tubule, mainly in rats, mice, and rabbits. The structural data are complemented by recent data on the location of the major transport- and transport-regulating proteins, revealed by morphological means(immunohistochemistry, immunofluorescence, and/or mRNA in situ hybridization). The structural differences along the uriniferous tubule strictly coincide with the distribution of the major luminal and basolateral transport proteins and receptors and both together provide the basis for the subdivision of the uriniferous tubule into functional subunits. Data on structural adaptation to defined functional changes in vivo and to genetical alterations of specified proteins involved in transepithelial transport importantly deepen our comprehension of the correlation of structure and function in the kidney, of the role of each segment or cell type in the overall renal function,and our understanding of renal pathophysiology.
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45
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Schiessl IM, Rosenauer A, Kattler V, Minuth WW, Oppermann M, Castrop H. Dietary salt intake modulates differential splicing of the Na-K-2Cl cotransporter NKCC2. Am J Physiol Renal Physiol 2013; 305:F1139-48. [PMID: 23946287 DOI: 10.1152/ajprenal.00259.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Both sodium reabsorption in the thick ascending limb of the loop of Henle (TAL) and macula densa salt sensing crucially depend on the function of the Na/K/2Cl cotransporter NKCC2. The NKCC2 gene gives rise to at least three different full-length NKCC2 isoforms derived from differential splicing. In the present study, we addressed the influence of dietary salt intake on the differential splicing of NKCC2. Mice were subjected to diets with low-salt, standard salt, and high-salt content for 7 days, and NKCC2 isoform mRNA abundance was determined. With decreasing salt intake, we found a reduced abundance of the low-affinity isoform NKCC2A and an increase in the high-affinity isoform NKCC2B in the renal cortex and the outer stripe of the outer medulla. This shift from NKCC2A to NKCC2B during a low-salt diet could be mimicked by furosemide in vivo and in cultured kidney slices. Furthermore, the changes in NKCC2 isoform abundance during a salt-restricted diet were partly mediated by the actions of angiotensin II on AT1 receptors, as determined using chronic angiotensin II infusion. In contrast to changes in oral salt intake, water restriction (48 h) and water loading (8% sucrose solution) increased and suppressed the expression of all NKCC2 isoforms, without changing the distribution pattern of the single isoforms. In summary, the differential splicing of NKCC2 pre-mRNA is modulated by dietary salt intake, which may be mediated by changes in intracellular ion composition. Differential splicing of NKCC2 appears to contribute to the adaptive capacity of the kidney to cope with changes in reabsorptive needs.
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Affiliation(s)
- Ina Maria Schiessl
- Institute of Physiology, Univ. of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany.
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Chang WJ, Wang YF, Hu HJ, Wang JH, Lee TH, Hwang PP. Compensatory regulation of Na+ absorption by Na+/H+ exchanger and Na+-Cl- cotransporter in zebrafish (Danio rerio). Front Zool 2013; 10:46. [PMID: 23924428 PMCID: PMC3750650 DOI: 10.1186/1742-9994-10-46] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 08/02/2013] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION In mammals, internal Na+ homeostasis is maintained through Na+ reabsorption via a variety of Na+ transport proteins with mutually compensating functions, which are expressed in different segments of the nephrons. In zebrafish, Na+ homeostasis is achieved mainly through the skin/gill ionocytes, namely Na+/H+ exchanger (NHE3b)-expressing H+-ATPase rich (HR) cells and Na+-Cl- cotransporter (NCC)-expressing NCC cells, which are functionally homologous to mammalian proximal and distal convoluted tubular cells, respectively. The present study aimed to investigate whether or not the functions of HR and NCC ionocytes are differentially regulated to compensate for disruptions of internal Na+ homeostasis and if the cell differentiation of the ionocytes is involved in this regulation pathway. RESULTS Translational knockdown of ncc caused an increase in HR cell number and a resulting augmentation of Na+ uptake in zebrafish larvae, while NHE3b loss-of-function caused an increase in NCC cell number with a concomitant recovery of Na+ absorption. Environmental acid stress suppressed nhe3b expression in HR cells and decreased Na+ content, which was followed by up-regulation of NCC cells accompanied by recovery of Na+ content. Moreover, knockdown of ncc resulted in a significant decrease of Na+ content in acid-acclimated zebrafish. CONCLUSIONS These results provide evidence that HR and NCC cells exhibit functional redundancy in Na+ absorption, similar to the regulatory mechanisms in mammalian kidney, and suggest this functional redundancy is a critical strategy used by zebrafish to survive in a harsh environment that disturbs body fluid Na+ homeostasis.
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Affiliation(s)
- Wei-Jen Chang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
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Liu T, Jose PA. Gastrin induces sodium-hydrogen exchanger 3 phosphorylation and mTOR activation via a phosphoinositide 3-kinase-/protein kinase C-dependent but AKT-independent pathway in renal proximal tubule cells derived from a normotensive male human. Endocrinology 2013; 154:865-75. [PMID: 23275470 PMCID: PMC3548178 DOI: 10.1210/en.2012-1813] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gastrin is natriuretic, but its renal molecular targets and signal transduction pathways are not fully known. In this study, we confirmed the existence of CCKBR (a gastrin receptor) in male human renal proximal tubule cells and discovered that gastrin induced S6 phosphorylation, a downstream component of the phosphatidylinositol 3 kinase (PI3 kinase)-mammalian target of rapamycin pathway. Gastrin also increased the phosphorylation of sodium-hydrogen exchanger 3 (NHE3) at serine 552, caused its internalization, and decreased its expression at the cell surface and NHE activity. The phosphorylation of NHE3 and S6 was dependent on PI3 kinases because it was blocked by 2 different PI3-kinase inhibitors, wortmannin and LY294,002. The phosphorylation of NHE3 and S6 was not affected by the protein kinase A inhibitor H-89 but was blocked by a pan-PKC (chelerythrine) and a conventional PKC (cPKC) inhibitor (Gö6976) (10 μM) and an intracellular calcium chelator, 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetra(acetoxymethyl)-ester, suggesting the importance of cPKC and intracellular calcium in the gastrin signaling pathway. The cPKC involved was probably PKCα because it was phosphorylated by gastrin. The gastrin-mediated phosphorylation of NHE3, S6, and PKCα was via phospholipase C because it was blocked by a phospholipase C inhibitor, U73122 (10 μM). The phosphorylation (activation) of AKT, which is usually upstream of mammalian target of rapamycin in the classic PI3 kinase-AKT-p70S6K signaling pathway, was not affected, suggesting that the gastrin-induced phosphorylation of NHE3 and S6 is dependent on both PI3 kinase and PKCα but not AKT.
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Affiliation(s)
- Tianbing Liu
- Center for Molecular Physiology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, Washington, DC 20010, USA.
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Lee DH, Maunsbach AB, Riquier-Brison AD, Nguyen MTX, Fenton RA, Bachmann S, Yu AS, McDonough AA. Effects of ACE inhibition and ANG II stimulation on renal Na-Cl cotransporter distribution, phosphorylation, and membrane complex properties. Am J Physiol Cell Physiol 2012; 304:C147-63. [PMID: 23114965 DOI: 10.1152/ajpcell.00287.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The renal distal tubule Na-Cl cotransporter (NCC) reabsorbs <10% of the filtered Na(+) but is a key control point for blood pressure regulation by angiotensin II (ANG II), angiotensin-converting enzyme inhibitors (ACEI), and thiazide diuretics. This study aimed to determine whether NCC phosphorylation (NCCp) was regulated by acute (20-30 min) treatment with the ACEI captopril (12 μg/min × 20 min) or by a sub-pressor dose of ANG II (20 ng·kg(-1)·min(-1)) in Inactin-anesthetized rats. By immuno-EM, NCCp was detected exclusively in or adjacent to apical plama membranes (APM) in controls and after ACEI or ANG II treatment, while NCC total was detected in both APM and subapical cytoplasmic vesicles (SCV) in all conditions. In renal homogenates, neither ACEI nor ANG II treatment altered NCCp abundance, assayed by immunoblot. However, by density gradient fractionation we identified a pool of low-density APM in which NCCp decreased 50% in response to captopril and was restored during ANG II infusion, and another pool of higher-density APM that responded reciprocally, indicative of regulated redistribution between two APM pools. In both pools, NCCp was preferentially localized to Triton-soluble membranes. Blue Native gel electrophoresis established that APM NCCp localized to ~700 kDa complexes (containing γ-adducin) while unphosphorylated NCC in intracellular membranes primarily localized to ~400 kDa complexes: there was no evidence for native monomeric or dimeric NCC or NCCp. In summary, this study demonstrates that phosphorylated NCC, localized to multimeric complexes in the APM, redistributes in a regulated manner within the APM in response to ACEI and ANG II.
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Affiliation(s)
- Donna H Lee
- Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
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Lessa LMA, Carraro-Lacroix LR, Crajoinas RO, Bezerra CN, Dariolli R, Girardi ACC, Fonteles MC, Malnic G. Mechanisms underlying the inhibitory effects of uroguanylin on NHE3 transport activity in renal proximal tubule. Am J Physiol Renal Physiol 2012; 303:F1399-408. [PMID: 22952280 DOI: 10.1152/ajprenal.00385.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We previously demonstrated that uroguanylin (UGN) significantly inhibits Na(+)/H(+) exchanger (NHE)3-mediated bicarbonate reabsorption. In the present study, we aimed to elucidate the molecular mechanisms underlying the action of UGN on NHE3 in rat renal proximal tubules and in a proximal tubule cell line (LLC-PK(1)). The in vivo studies were performed by the stationary microperfusion technique, in which we measured H(+) secretion in rat renal proximal segments, through a H(+)-sensitive microelectrode. UGN (1 μM) significantly inhibited the net of proximal bicarbonate reabsorption. The inhibitory effect of UGN was completely abolished by either the protein kinase G (PKG) inhibitor KT5823 or by the protein kinase A (PKA) inhibitor H-89. The effects of UGN in vitro were found to be similar to those obtained by microperfusion. Indeed, we observed that incubation of LLC-PK(1) cells with UGN induced an increase in the intracellular levels of cAMP and cGMP, as well as activation of both PKA and PKG. Furthermore, we found that UGN can increase the levels of NHE3 phosphorylation at the PKA consensus sites 552 and 605 in LLC-PK(1) cells. Finally, treatment of LLC-PK(1) cells with UGN reduced the amount of NHE3 at the cell surface. Overall, our data suggest that the inhibitory effect of UGN on NHE3 transport activity in proximal tubule is mediated by activation of both cGMP/PKG and cAMP/PKA signaling pathways which in turn leads to NHE3 phosphorylation and reduced NHE3 surface expression. Moreover, this study sheds light on mechanisms by which guanylin peptides are intricately involved in the maintenance of salt and water homeostasis.
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Affiliation(s)
- Lucília M A Lessa
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo/SP, Brazil.
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Cabral EV, Vieira-Filho LD, Silva PA, Nascimento WS, Aires RS, Oliveira FST, Luzardo R, Vieyra A, Paixão ADO. Perinatal Na+ overload programs raised renal proximal Na+ transport and enalapril-sensitive alterations of Ang II signaling pathways during adulthood. PLoS One 2012; 7:e43791. [PMID: 22928034 PMCID: PMC3425503 DOI: 10.1371/journal.pone.0043791] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/24/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND High Na(+) intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na(+) overload-programmed alterations in Na(+) transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. METHODOLOGY/PRINCIPAL FINDINGS Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na(+)+K(+))ATPase expression and activity. Ouabain-insensitive Na(+)-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT(2) receptor expression decreased while AT(1) expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na(+)+K(+))ATPase, partially recovered the response of Na(+)-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na(+) or not. In addition, treatment with enalapril per se reduced AT(2) receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na(+)-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. CONCLUSIONS/SIGNIFICANCE Maternal Na(+) overload programmed alterations in renal Na(+) transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril was beneficial predominantly through its influence on Na(+) pumping activities in adult offspring. However, side effects including down-regulation of PKA, PKC and AT(2) receptors and increased TBARS could impair renal function in later life.
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Affiliation(s)
- Edjair V. Cabral
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Leucio D. Vieira-Filho
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Paulo A. Silva
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Williams S. Nascimento
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Regina S. Aires
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Fabiana S. T. Oliveira
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Ricardo Luzardo
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Ana D. O. Paixão
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- * E-mail:
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